Disgraced cricket mogul and financier Allen Stanford and his wife owe at least 227 million dollars in back taxes, US tax officials said in court filings Monday.

The Texas billionaire's assets, along with those of his various financial groups, are frozen pending the outcome of a civil lawsuit in which securities officials accuse him of perpetuating a 9.2 billion dollar fraud.

The Internal Revenue Service asked the federal judge overseeing the case to add it to the lengthy line of Stanford's creditors and warned the bill could be even higher because Stanford has not yet filed his 2007 tax returns.

The IRS said in a motion filed on Friday that Stanford and his wife owed 110 million dollars in taxes and 116.5 million in penalties and interest for the years 1999 through 2003.

The agency asked the judge to order Stanford to file his 2007 taxes and grant the IRS permission to sue Stanford and his wife, Susan Stanford, for back taxes.

Stanford informed the court last week that he will exercise his constitutional guarantee against self-incrimination and will not testify or cooperate with investigators from the Securitites and Exchange Commission (SEC).

Stanford, a wealthy cricket impresario, has not faced criminal charges but the chief investment officer of his financial group, Laura Pendergest-Holt, was arrested last month and charged with obstructing an investigation.

Several governments have seized Stanford banks and frozen their assets with concern mounting that the global reach of the billionaire's banking operations could complicate the return of an estimated 50 billion dollars in assets belonging to an estimated 50,000 clients in 140 countries.

The case was the highest-profile alleged fraud scheme to emerge since the SEC charged Wall Street financier Bernard Madoff with carrying out a 50-billion-dollar Ponzi scheme in December.

Stanford was behind the high-profile Stanford Super Series Twenty20 competition.

On February 17, the SEC accused Stanford of perpetrating "a fraud of shocking magnitude that has spread its tentacles throughout the world," by luring investors with "improbable and unsubstantiated" returns.